Bathing bearded dragons helps to hydrate, and has an added bonus of cleaning your bearded dragon.
Equipment for bathing
Containers are sufficient to bathe in. Household bath tubs or sinks are not necessary, can be too large and present cleaning issues especially since bathing encourages bowel movements. A rock, log or any other appropriate object can be used in the bath for respite if the animal becomes distressed, however a hand will do just as well.

A thermometer is handy for anyone unsure of what temperature the water is, the are cheap and readily available.
Temperature for bathing
The water should be luke warm which, according to Mosby’s Medical Dictionary, is between 90-96ºF (32-36ºC). This is within the range of basking temperatures making it ideal. Using a thermometer will assist when first starting until you get accustomed to what that temperature feels like to touch. Ensure the water doesn’t cool to much while your bearded dragon is bathing especially if it has recently eaten.
Duration and frequency of bathing
As part of a hydrating routine or to aid in shedding, up to 20 minutes of bathing will be sufficient, for constipation bathe for 1/2 an hour or so keeping the temperature luke warm. Bathing is an excellent means of encouraging bowel movements, especially if experiencing constipation.
The schedule for bathing depends on what other hydrating methods are being used, how often they are used and the environment the bearded dragon is kept in (i.e. the humidity level is too low). Given that, if bathing is to be a part of the hydration routine then weekly should be sufficient.
Bathing bearded dragons technique to reduce stress of bathing
Fred has been patiently introduced to bathing which has paid off by making it enjoyable for all involved. Fred/Wilma the Bearded Dragon
To start bathing keep the water shallow, little more than a puddle to assist in their comfort. If the bearded dragon enjoys it, then the water level can be taken up enough to swim which will aid in providing exercise, however it may take some time before they truly enjoy it and in some cases they never will.
Place an object in the water such as a rock so they can move out of the water as they want. Just scoop the water by hand and pour it over the animals body if it stays on the object provided.
Using a soft toothbrush, stroke its body with the bristles. This will probably be most enjoyable during shedding.
Is your bearded dragon swimming or scared?
There is no need for the water to be deep enough to have to swim, they are not aquatic and it may result in fear. Swimming is not necessarily a sign of enjoyment, but of survival. If placed in water deep enough to swim and it continually swims towards the edge and keeps swimming against the edge, the odds are it is scared. If you are unsure, then put an object in the water. If it chooses to stay on the object then it is unlikely it was enjoying the depth of the bath provided. Some bearded dragons will bloat or puff out when bathing, this will assist in buoyancy.
Stress causes illness and is cruel to inflict. If it becomes distressed during bathing then the method of bathing needs to be modified (i.e. smaller volume of water, hand for support) or cease bathing altogether. It is not necessary to bathe and there are other means to provide hydration.
Poop in the bath!
It is extraordinarily common when bathing bearded dragons for them to poop in the bath, expect it! If the bowels move while in the bath, either remove the faeces before it gets mixed into the bath water or end the bathing session. Do not leave them bathing in their own bowel movements.

Outdoor bathing
Bathing bearded dragons outdoors provides the opportunity for UVB as well as hydration if the weather is suitable.
Be cautious if using an outdoor hose on your bearded dragon, not only could the water pressure be to harsh but there is no way to regulate the temperature.
Drying
Once bathing has finished, it can be put back in the enclosure without drying, towel drying is not necessary.
In this video Ljupce goes through how to provide a bath so that your bearded dragon is safe and secure.
john
Wednesday 31st of October 2018
actually you should let them dry off before going in theyre terrarium if there is sand because i could irritate their bellys
Chris
Tuesday 13th of November 2018
That could be more comfortable if loose substrate is being used.